Toys for use in water tend to fall into a small number of types. There are floating devices such as rubber ducks. There are squirting devices like squirt guns. There are small numbers of animals which absorb water to expand from a tiny size to a small size. However, there are a limited number of scientific toys.
Scientific toys for the bath tend to be demonstrations of buoyancy: submarines and the like. One typical item would be U.S. Pat. No. 4,206,565 issued Jun. 10, 1980 to Goldfarb.
While there are references to “whirlpool bathtubs”, these are not toys at all but rather bathtubs with jets to provide a massage to a user of the tub. U.S. Design Patent D428155 issued to Chalberg et al Jul. 11, 2000 is an example of this, as is U.S. Design Patent D310717 issued to Heiligenstein on Sep. 18, 1990.
Another category of items concerns water park and amusement park rides. A number of such devices have whirlpools, waves, tubes or the like. U.S. Pat. No. 5,616,083 issued to Subbaraman et al on Apr. 1, 1997 is an example of this, as is U.S. Pat. No. 586,718 issued Jul. 20, 1897 to Wharton, Jr.
Another category of items are devices for use in creating an air vortex using a fan, air jets, and similar items. U.S. Pat. No. 5,096,467 issued to Matsui on Mar. 17, 2002 is an example of this.
Yet another type of item is material handling apparatus for scientific or production work, for example, U.S. Pat. No. 3,372,873 issued to Weiss on Mar. 12, 1968.
Finally, a number of display items having clear cylindrical sides and machinery for creating a whirlpool in a standing body of liquid within the cylinder are known. These do not relate to bathtubs, drain powered vortexes or the like. Examples include: U.S. Pat. No. 4,258,912 issued Mar. 31, 1981 to Reighart, II and U.S. Pat. No. 5,272,604 to Lin on Dec. 21, 1993, and U.S. Pat. No. 6,241,359 issued Jun. 5, 2001 to Lin and U.S. Pat. No. 6,295,749 issued Oct. 2, 2001 to Lin and U.S. Pat. No. 6,681,503 issued Jan. 27, 2004 to Unger et al.
None of the cited references teach that an ordinary, non-jetted bathtub drain may be used to power s whirlpool for education and amusement of children. None of these devices teach a cylindrical body having a drain dimensioned and configured to sit atop a household bath or sink drain, a recuperation chamber, a gasket sized to secure the device to a bathtub surface, and a hole having liquid access to a household drain.